Heterogeneous Traffic Induced Effects on Vertical Dispersion Parameter in the Near Field of Roadways - a Wind Tunnel Study

The varying traffic parameters such as traffic volume, speed, shape and size, and terrain roughness conditions play a vital role on dispersion of pollutants in the near field of roadways. Simulation experiments were carried out in the Environmental Wind Tunnel (EWT) to evaluate the traffic induced effects on vertical dispersion parameter (σ _z ) for heterogeneous traffic conditions in the near field of roadways for evaluating the effect of variations in traffic volume, terrain roughness condition and approaching wind direction. The model vehicle movement system was fabricated and made operational in the EWT, which allowed the variation in traffic volume, speed and wind road inclination. Sixty-six hydrocarbon tracer experiments were performed to evaluate σ _z in the near field of roadways for variable traffic volume, three terrain roughness conditions and two approaching wind directions (i.e., 90° and 60°). The values of σ _z for heterogeneous traffic conditions were found to be higher for low roughness conditions in comparison to other two higher roughness conditions for various traffic volumes and approaching wind directions. This revised version was published online in July 2006 with corrections to the Cover Date.     

长乐—南澳变质带显微构造和岩组特征及应力场分析

通过光学显微镜和高压电子显微镜对带内的变形石英进行显微构造超微构造观测和估算变形参数(σ_1-σ_3=85.0MPa,ε_s=10~(-9)～10~(-10)/S),认为该区变质岩形成于深层环境,是长期缓慢变形的结果。变形石英位错构造为变形阶段和恢复阶段的混合体,其变形机制为塑性形变。采用石英光轴干涉图法,在偏光显微镜下对水平定向薄片进行岩组测量,绘制成该区的石英光轴方位图,探讨其构造变形的演化历史。首次划分出S(或S+S)和B+S构造岩岩组类型及Ⅰ型、Ⅳ型和Ⅴ型石英定向类型。应力场随着构造变形的演化作逆时针旋转。山南北挤压应力场逐渐变为单向推挤的应力场,从而认为构造变形是多期次的叠加。     

单一重现期非线性暴雨强度模型参数的确定--新型混合加速遗传算法的构建与应用

对浮点编码遗传算法进行了改进,并嵌入Powell方向加速局部搜索算法与加速循环操作,从而构建了新型混合加速遗传算法.确定单一重现期的非线性暴雨强度模型参数的应用实例表明,该方法兼顾了改进浮点编码遗传算法和Powell算法的优点,是一种既可以较大概率、快速地搜索全局近似最优解,又能进行局部细微搜索的出色的非线性优化方法.该法在其它工程问题的非线性模型参数的确定中也具有广阔的应用前景.     

渤海PL19-3油田设计地震动参数研究

渤海PL19-3油田按美国有关规范进行抗震设计,其抗震设防标准和地震动参数与我国有关技术规范相比均存在一定的差别。本文根据渤海及邻区的地震构造、地震活动环境的研究结果,以及工程场地的钻探资料、土动力参数测试结果,参照美国有关技术规范的方法,确定了PL19-3油田的设计地震动参数。研究成果不但能满足该工程的抗震设计需要,也可供渤海海域其他工程参考,尤其是所得到的场地土动力学参数具有其特殊性和代表性。本工作将促进海洋工程的抗震技术规范和设防标准的研究,同时,也为未来开展海域地震区划工作积累了基础资料和工作方法。     

国内外地震滑坡灾害研究综述

对地震灾害较严重的美国、意大利、希腊等国家在地震滑坡灾害方面所做的研究工作进行了总结,并与我国的研究成果进行了对比。给出了国内外对地震滑坡的分类，论述了地震滑坡在面积范围、密度及滑坡体积等方面与地震震级、地震烈度、震中距等参数之间的关系；对地震时易于触发滑坡的地貌坡度及地质构造等因素进行了分析。最后对国外地震滑坡灾害预测研究进行了概述。     

加速量热仪在物质热稳定性研究中的应用

加速量热仪（ARC）是一种基于绝热原理设计的热分析仪器,与其它热分析仪器相比,加速量热仪可以测量克量级的固体或高闪点液体样品,具有测试样品最大,敏感度高等特点,并能够实时记录样品放热反应过程中的温度和压力变化,以过氧化氢叔丁基为例说明加速量热仪测试结果在研究物质质变热稳定性方面的应用,得到了过氧化氢叔丁基放热分解反应的温度－时间和压力－时间关系曲线以及升温速度和压力随温度变化的曲线,通过计算和分析得到了反应系统升压速率随压力的变化曲线,计算出了过氧化氢叔丁基分解反应的动力学参数表观活化能Ea和指前因子A。     

基于反距离加权插值法评价海域水质类别空间分布

空间插值技术可以对污染物分布状况进行面状连续表征,是对点位法评价的有效补充。笔者根据现行海水水质评价方法,类比给出近岸海域水质类别空间分布评价的流程:单指标空间插值-单指标水质分类-多指标水质类别判定。研究了反距离加权插值参数的选取方法,并以点位密度不同的全国近岸海域(开放型)和渤海海域(近封闭型)为例进行了插值实验。 结果表明:对目前的点位分布情况而言,全国近岸海域参数设为p=3,N=4, C=200m较为适宜;渤海海域参数为p=2,N=5,C=200m较为适宜。反距离加权插值法在开放海域的拟合效果要优于近封闭海域。     

A community driving under the influence (DUI) study of declining arrests

Abstract

Objective: Recent news reports in 2016 indicated that across Miami–Dade County, Florida, driving under the influence (DUI) arrests have decreased substantially. The objective of this research was to determine the reasons for the decline in DUI arrests from 2009 to 2016. Are there fewer impaired drivers on the roads? Can DUI enforcement and prosecution be improved?

Methods: The following methods were used in this study: (1) Analysis of existing DUI arrest and crash data; (2) conducting and analysis of a telephone survey of reported knowledge, attitudes, and behaviors concerning impaired driving; (3) conducting and analysis of roadside surveys on the roads on weekend nights in Miami–Dade County; (4) information from focus group discussions with police and prosecutors in Miami–Dade County; and (5) a comprehensive review of the best DUI prevention practices and enforcement strategies used across the country.

Results: DUI arrests decreased 64% in Miami–Dade County between 2009 and 2016. This was a significantly larger decrease than has occurred in the State of Florida as a whole (34%) and in the United States (29%) over the same time period. The decline was not due to any decline in DUI behavior in the county.

Conclusions: Based upon the data and information gathered in this project, the following actions were recommended for Miami–Dade County: (1) County police chiefs need to find ways to overcome law enforcement apathy toward DUI enforcement and persuade their traffic enforcement officers to be proactive rather than reactive when it comes to identifying and making impaired driving stops. (2) County police agencies should join forces to conduct more sobriety checkpoints. Checkpoints are safer for both the police and the drivers going through them and serve as a general deterrent to impaired driving. (3) An interagency DUI task force or team of 5 to 7 officers should be established within the county. These officers would be solely dedicated to DUI enforcement and paid for by each individual agency or under a grant from the state or federal government.     

供风量对褐煤自燃极限参数的影响研究

为研究不同供风量对褐煤自燃特性的影响规律,选取平庄瑞安煤矿褐煤作为试验煤样,利用程序升温试验和气相色谱仪,研究低温氧化阶段不同供风量条件下褐煤自燃极限参数与温度、供风量之间的变化规律。结果表明:温度在40~120℃时,随着供风量增大,褐煤的最小浮煤厚度和下限氧浓度降低,上限漏风强度增加;温度在120~200℃,供风量为40~80 mL/min和160~200 mL/min时,随着供风量的增加,其最小浮煤厚度和下限氧浓度增加,上限漏风强度减少;供风量为80~160 mL/min时,在供风量增大的情况下,褐煤的最小浮煤厚度和下限氧浓度降低,上限漏风强度增加;随着供风量减小,煤样临界点温度降低。     

石化企业储罐大呼吸损耗影响因素的分析

储罐是石化行业挥发性有机物(VOCs)无组织排放源的重要组成部分。采用美国环保署推荐的储罐VOCs排放量计算公式,以云南某炼化企业的典型热渣油立式固定顶罐以及北京某石化企业的汽油外浮顶罐和甲苯内浮顶罐为基准案例进行储罐大呼吸损耗量的计算,考察了其影响因素,总结出影响储罐大呼吸损耗的关键参数,并有针对性地提出降耗措施。结果表明:影响固定顶罐大呼吸损耗的关键参数为气相分子摩尔质量、日平均液体表面温度和年周转量;影响外浮顶罐大呼吸损耗的首要关键参数为罐壁黏附系数,其次为年周转量和有机液体的密度;影响内浮顶罐大呼吸损耗的首要关键参数为罐壁黏附系数,其次为年周转量和固定顶支撑柱数量。